Improvement in projectiles for rifled ordnance



J. H. MERRILL.

Projectile.

Patented Oct. 13, 1857 TATES NITED ATENT rrrcn.

JAMES H. MERRILL, OF BALTIMORE-MARYLAND.

Specification forming part of Letters Patent N0. 18,401, dated October13, 1857.

To all whom it may concern Be it known that I, J AMES H. MERRILL, ofBaltimore, in the county of Baltimore and State of Maryland, haveinvented certain new and useful Improvements in the Construction ofProjectiles; and I do hereby declare the following to be a full, clear,and exact descrip tion of the same, reference being had to theaccompanying drawings, making a part of this specification, in whichFigure 1 represents the projectile in perspective. Fig. 2 represents avertical section through the same, and Fig. 3 represents a hori zontalsection taken at the red linew x of Fig. 2.

Similar letters of reference, where they occur in the separate figures,denote like parts of the projectile in all of them.

My invention relates to that class of projectiles in which the base orrear portion is caused to be expanded by the gas to fill the bore of thegun; but, unlike all other projectiles of this class, I make mine of onepiece of cast-iron, and cause a portion of this castiron to be expanded,instead of packing the projectile with lead or inserting in it sectionsof wrought-iron, as have been done, to fill the bore.

Making projectiles of two kinds of metals, or even in two or morepieces, is not only expensive, but the parts will separate or fly fromeach other under the concussion of the discharge, and make their rangeuncertain, as well as to be dangerous. I therefore make my projectile inone single piece, but still preserve the expanding property. It is bestmade of cast-iron, annealed, if found desirable, to give it propertenacity, though it may be made, but at greatly increased expense, ofwrought-iron; and I would consider the latter metal almost out of thequestion, owing to the expense of making the projectile, when thecast-iron can be softened, or left hard when the projectile is to be anexplosive one.

To enable others skilled in the art to make and use my invention, I willproceed to describe the same with reference to the drawings. Arepresents a conical-shaped projectile,

having its base rounded out, as shown at a,

and hollow, so that the powder may enter and explode therein. The rim 6,between the outer edge of the shot and the chamber or bore a, is quitethin at the extreme rear end; but it gradually thickens until at a linedrawn through the bottom of the chamber its solidity would prevent itfrom being expanded by the gas. At a point, 0, (say about midway betweenthe rear of the projectile and the bottom of the chamber or bowl (1-,)are made through the wall of the chamber or bowl any suitable number ofholes, 1 2 3, and from the rear of the projectile slots 4 are formed orcut down to said holes, so as to leave the base of the projectile, as itwere, in sections.

5 5 5 are ribs or swells on the outside of the projectile, which areintended to fit into the grooves or rifles of the cannon, and around theoutside of the projectile is placed a band or fillet of leather, 6,india-rubber, or other material, which will close the slots 4 to keepthe gas from getting between the projectile and the bore of the gun, butat the same time yield to the expansion of the sections between theslots, and it is immaterial whether the fillet adheres to the ball orprojectile or not after it leaves the gun, its object having been exhansted before the projectile leaves the gun.

If that part of the projectile which is to be expanded to fit the borebe annealed or made of malleable cast-iron, there is no possible dangerof the sections being broken, as they will easily spring by theexpansion of the gas to the necessary extent to accomplish the purpose,the spring being gradual from the holes 1 2 3 to the rear of theprojectile, and the metal thinning in the same direction, the slots ofcourse widening to admit of the expansion.

Having thus fully described the nature and object of my invention, whatI claim therein as new, and desire to secure by Letters Patent, is

Making the base of a projectile that is cast in one piece cup or bowlshaped, and slotting the metal between the hollow and the outside of theprojectile, so as to allow said base to expand by the force of the gasto fill the grooves or bore of the gun, substantially as described.

J AMES H. MERRILL.

Witnesses:

E. BEATTY GRAFF, Enwni G. STARR.

